Google is to shorten the time it keeps the search data it collects; the data will now be kept for 18 months instead of the previous 24. It's a move which the EU has said it welcomes, as information contained in the data could potentially identify individual users.

"It is indeed a good step," the EU justice chief Franco Frattini said today. Frattini added that he appreciated the "commitment of Google" in not only meeting his expectations concerning privacy protection, but bettering them.

Google has been criticised by the EU's Article 29 working party , which works with protecting personal information, for the way it retains data. The new 18 month promise is six months less than it suggested in March. After that threshold has passed data will then be made anonymous.

"After considering the working party's concerns, we are announcing a new policy to anonymise our search server logs after 18 months, rather than the previously established period of 18 to 24 months," said Google global privacy counsel Peter Fleisher.

The Article 29 working party includes national data protection supervisors from the 27 EU states. It said in May that Google seems to ignore the EU's rules on integrity, before questioning why it needed the data for so long. The working party asked Google to clarify how it uses the information before its next meeting in June.

Google stores past user queries for analysis and security reasons, according to Fleisher, allowing the firm to improve the quality of search results and track down click fraud. "We firmly reject any suggestions that we could meet our legitimate interests in security, innovation and anti-fraud efforts with any retention period shorter than 18 months," he added.

EU regulations dictate that data should be stored "in a form which permits identification of data subjects for no longer than is necessary for the purpose for which the data [was] collected or for which [it is] further processed".

The original Article 29 working party complaint can be seen here , and Google's reply here .